It is known to use transparent templates, swivel blade knives, and flat graphic art objects mounted on adhesive coated substrates to produce picture puzzle pieces. The templates are formed with a plurality of through cuts that form channels which define outlines of a plurality of puzzle pieces. The channels are interrupted and interconnected by webs to prevent the puzzle pieces patterns from separating from the template. The widths of the channels are established according to the thickness of the knife blade so as to permit the knife blade to enter the channels and move therethrough, but to limit side to side movement of the knife blade, to assure that the cuts made by the knife are exact. The linear patterns of the channels are configured to accommodate the turning ability of the knife blade, allowing the blade to advance freely. By aligning a workpiece, comprising a photograph, or other flat graphic art object mounted on a substrate, under the template, puzzle pieces can be cut from the photograph or other graphic art object.
The template preferably is of a clear, transparent material. The knife preferably is a swivel knife which cuts the photograph or other graphic art object and the substrate along lines corresponding to the channels in the template. The knife is dimensioned to fit into and follow the configuration of the channels in the template. The substrate is adhesively coated, such that the graphic art object may be adhered thereto prior to cutting. The adhesive layer of the substrate is pressure sensitive and bonds the back of the graphic art object to the substrate. The cutting depth of the knife blade is sufficient to penetrate the thickness of the template, the photograph or other graphic art object, and the adhesive-coated substrate, to provide a picture puzzle piece of laminated structure.
After cutting along the template channel, a straight knife may be used to complete the outline of the puzzle piece and thereby separate the puzzle piece from the workpiece.
Referring to FIG. 1, it will be seen that the swivel knife 10 may include a handle portion 12 for manipulation by an operator, which may be a person or a machine, and a knife blade 14 that is mounted on the handle portion 12 so that the blade is capable of a swivel motion relative to the handle, that is, such that the blade 14 can rotate on the axis of the handle portion 12 of the knife 10.
Referring still to FIG. 1, assume that a puzzle piece is to be produced conforming in shape and size to puzzle piece pattern 16 in a template 18, the pattern being defined by channels 20a-20c. The knife blade 14 is positioned in one of the channels 20a-20c, such as channel 20a, such that the knife blade penetrates completely through the template 18 and a workpiece 22, which includes the graphic art object 24 and the substrate 26 to which the art object 24 is adhered by a layer of adhesive 28. The knife blade 14 is then drawn along the length of the channel 20a, and thereafter along the lengths of the channels 20b and 20c.
The template 18 is removed, leaving the workpiece 22 with cuts corresponding to the channels 20a-20c. The webs between the cuts are then severed, as by a straight knife (not shown) to permit separation of the puzzle piece from the remainder of the workpiece. The foregoing procedure is repeated to produce additional interlocking puzzle pieces.
The method described briefly above, and the components of the assembly, and knife, are shown and described in detail in U.S. patent application Ser. No. 08/905,989, filed Aug. 5, 1997, in the name of Richard L. Lariviere, Jr., et al.
While the above-described method and components have satisfactorily produced a large number of picture puzzles, it has been found that on occasion the knife blade 14, as it travels along the channels, and particularly when encountering a relatively sharp bend in a channel, bites into a side of the channel, damaging the template 18 and/or blade 14.
Accordingly, there is a need for a knife blade of the type described above, provided with means for preventing the blade from cutting engagement with the walls of the channel through which the blade is drawn.